Has anyone changed the fluid in their TR-3650? The manual calls for Mercon ATF and I would imagine a fully synthetic Mercon ATF would only benefit the transmission. What types of Mercon ATF have people tried with good results? Mobil 1 ATF? Amsoil Universal ATF? Redline D4?

Does Ford fill the rear 8.8" with synthetic 75W-140 from the factory?

 

Pretty sure both are synthetic fill from the factory, so replacing them won't really help much. Both of these parts will probably last the lifetime of the car with zero maintenance.

 

I'm going to jump in one this one. I know that this has been discussed a thousand times in this forum, but that was nearly a year ago, and there seemed to be some concern regarding certain components in the trans that were made of paper, that would not do well with synthetic. I have heard in this forum that synthetic in the trans could actually make the car harder to shift.

What I'd like to know is- for those of you running Royal Purple, I have heard of 2 different Royal Purple products being used in the manual trans. I called Royal Purple, and they said to put in the "synchromax", but I have seen here that people are putting in the Royal Purple ATF.

Whish one should we be running?

 

I found a US/Mexican Tremec TR-3650 catalog PDF that has spare parts and diagrams. The capacity was listd as "3.8L" and the lube should be "Mobil 1 ATF". I've seen capacities ranging from 3.0L, 3.2L (owner's manual), 3.6L (Factory service manual), to 3.8L (Tremec parts catalog).

 

I have been using Royal Purple ATF in my trans for a year with no issues. I also use their 75-140 in the diff.

 

So, you are not using the Synchromax? It looks like you have the choice between their ATF and Synchromax.

 

I am running the synchromax and it works very well. It says on the bottle that it is formulated for use in manual transmissions that use ATF. Capacity is 3.2 quarts which is right at the threads of the fill plug so you can't really overfill it.

 

I am just using the standard ATF. I would go with the Syncromax though.